1. Unicast - the process of sending a packet from one host to an individual host. Presentation_ID 20 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv4 Unicast, Broadcast, and Multicast Broadcast Transmission 2. Broadcast - the process of sending a packet from one host to all hosts in the network Routers do not forward a limited broadcast! Directed broadcast Destination 172.16.4.255 Hosts within the 172.16.4.0/24 network Presentation_ID 21 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv4 Unicast, Broadcast, and Multicast Multicast Transmission Multicast - the process of sending a packet from one host to a selected group of hosts, possibly in different networks Reduces traffic Reserved for addressing multicast groups - 224.0.0.0 to 239.255.255.255. Link local - 224.0.0.0 to 224.0.0.255 (Example: routing information exchanged by routing protocols) Globally scoped addresses - 224.0.1.0 to 238.255.255.255 (Example: 224.0.1.1 has been reserved for Network Time Protocol)

Presentation_ID 22 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv4 Address Public and Private IPv4 Addresses Private address blocks are: Hosts that do not require access to the Internet can use private addresses 10.0.0.0 to 10.255.255.255 (10.0.0.0/8) 172.16.0.0 to 172.31.255.255 (172.16.0.0/12) 192.168.0.0 to 192.168.255.255 (192.168.0.0/16) Shared address space addresses: Not globally routable Intended only for use in service provider networks Address block is 100.64.0.0/10 Presentation_ID 23 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv4 Address Special Use IPv4 Addresses Network and Broadcast addresses - within each network the first and last addresses cannot be assigned to hosts Loopback address - 127.0.0.1 a special address that hosts use to direct traffic to themselves (addresses 127.0.0.0 to 127.255.255.255 are reserved) Link-Local address - 169.254.0.0 to 169.254.255.255 (169.254.0.0/16) addresses can be automatically assigned to the local host TEST-NET addresses - 192.0.2.0 to 192.0.2.255 (192.0.2.0/24) set aside for teaching and learning purposes, used in documentation and network examples Experimental addresses - 240.0.0.0 to 255.255.255.254 are listed as reserved Presentation_ID 24 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv4 Address Legacy Classful Addressing Presentation_ID 25 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv4 Address Legacy Classful Addressing Classless Addressing Formal name is Classless Inter-Domain Routing (CIDR, pronounced cider Created a new set of standards that allowed service providers to allocate IPv4 addresses on any address bit boundary (prefix length) instead of only by a class A, B, or C address

Presentation_ID 26 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv4 Address Assignment of IP Addresses Regional Internet Registries (RIRs) The major registries are: Presentation_ID 27 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv4 Address Assignment of IP Addresses Tier 2 ISPs generally focus on business customers. Tier 3 ISPs purchase their Internet service from Tier 2 ISPs. Tier 3 ISPs often bundle Internet connectivity as a part of network and computer service contracts for their customers. ISPs are large national or international ISPs that are directly connected to the Internet backbone. Presentation_ID 28 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 8.2 IPv6 Network Addresses Presentation_ID 29 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv4 Issues The Need for IPv6 IPv6 is designed to be the successor to IPv4 Depletion of IPv4 address space has been the motivating factor for moving to IPv6 Projections show that all five RIRs will run out of IPv4 addresses between 2015 and 2020 With an increasing Internet population, a limited IPv4 address space, issues with NAT and an Internet of things, the time has come to begin the transition to IPv6! Presentation_ID 30 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv4 Issues The Need for IPv6 IPv4 has theoretical maximum of 4.3 billion addresses plus private addresses in combination with NAT IPv6 larger 128-bit address space providing for 340 undecillion addresses IPv6 fixes the limitations of IPv4 and include additional enhancements such as ICMPv6 Presentation_ID 31 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv4 Issues IPv4 and IPv6 Coexistence The migration techniques can be divided into three categories: #1 Dual-stack: Allows IPv4 and IPv6 to coexist on the same network. Devices run both IPv4 and IPv6 protocol stacks simultaneously. Presentation_ID 32 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv4 Issues IPv4 and IPv6 Coexistence The migration techniques can be divided into three categories: #2 Tunnelling: A method of transporting an IPv6 packet over an IPv4 network. The IPv6 packet is encapsulated inside an IPv4 packet. Presentation_ID 33 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv4 Issues IPv4 and IPv6 Coexistence The migration techniques can be divided into three categories: #3 Translation: Network Address Translation 64 (NAT64) allows IPv6-enabled devices to communicate with IPv4-enabled devices using a translation technique similar to NAT for IPv4. An IPv6 packet is translated to an IPv4 packet, and vice versa. Presentation_ID 34 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv6 Addressing Hexadecimal Number System Hexadecimal is a base sixteen system Base 16 numbering system uses the numbers 0 to 9 and the letters A to F Four bits (half of a byte) can be represented with a single hexadecimal value

Hextet used to refer to a segment of 16 bits or four hexadecimals Can be written in either lowercase or uppercase

Presentation_ID 37 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv6 Addressing Rule 1- Omitting Leading 0s The first rule to help reduce the notation of IPv6 addresses is any leading 0s (zeros) in any 16-bit section or hextet can be omitted 01AB can be represented as 1AB 09F0 can be represented as 9F0 0A00 can be represented as A00 00AB can be represented as AB

Presentation_ID 38 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv6 Addressing Rule 2- Omitting All 0 Segments A double colon (::) can replace any single, contiguous string of one or more 16-bit segments (hextets) consisting of all 0s Double colon (::) can only be used once within an address otherwise the address will be ambiguous Known as the compressed format Incorrect address - 2001:0DB8::ABCD::1234

Presentation_ID 42 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv6 Addresses IPv6 Unicast Addresses Unicast Uniquely identifies an interface on an IPv6-enabled device A packet sent to a unicast address is received by the interface that is assigned that address.

Presentation_ID 43 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv6 Addresses IPv6 Unicast Addresses Presentation_ID 44 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv6 Addresses IPv6 Unicast Addresses Global unicast Similar to a public IPv4 address Globally unique Internet routable addresses. Can be configured statically or assigned dynamically Link-local Used to communicate with other devices on the same local link Confined to a single link - not routable beyond the link Presentation_ID 45 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv6 Addresses IPv6 Unicast Addresses Loopback Used by a host to send a packet to itself and cannot be assigned to a physical interface Ping an IPv6 loopback address to test the configuration of TCP/IP on the local host All-0s except for the last bit, represented as ::1/128 or just ::1 Unspecified address All-0s address represented as ::/128 or just :: Cannot be assigned to an interface and is only used as a source address An unspecified address is used as a source address when the device does not yet have a permanent IPv6 address or when the source of the packet is irrelevant to the destination Presentation_ID 46 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv6 Addresses IPv6 Unicast Addresses Unique local Similar to private addresses for IPv4 Used for local addressing within a site or between a limited number of sites In the range of FC00::/7 to FDFF::/7 IPv4 embedded (not covered in this course) Used to help transition from IPv4 to IPv6 Presentation_ID 47 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv6 Addresses IPv6 Link-Local Unicast Addresses Every IPv6-enabled network interface is REQUIRED to have a link-local address Enables a device to communicate with other IPv6-enabled devices on the same link and only on that link (subnet) FE80::/10 range, first 10 bits are 1111 1110 10xx xxxx 1111 1110 1000 0000 (FE80) - 1111 1110 1011 1111 (FEBF) Presentation_ID 48 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Types of IPv6 Addresses IPv6 Link-Local Unicast Addresses Packets with a source or destination link-local address cannot be routed beyond the link from where the packet originated

Presentation_ID 49 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv6 Unicast Addresses Structure of an IPv6 Global Unicast Address IPv6 global unicast addresses are globally unique and routable on the IPv6 Internet Equivalent to public IPv4 addresses ICANN allocates IPv6 address blocks to the five RIRs Currently, only global unicast addresses with the first three bits of 001 or 2000::/3 are being assigned Presentation_ID 50 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv6 Unicast Addresses Structure of an IPv6 Global Unicast Address Currently, only global unicast addresses with the first three bits of 001 or 2000::/3 are being assigned

Global Routing Prefix- prefix or network portion of the address assigned by the provider, such as an ISP, to a customer or site, currently, RIRs assign a /48 global routing prefix to customers 2001:0DB8:ACAD::/48 has a prefix that indicates that the first 48 bits (2001:0DB8:ACAD) is the prefix or network portion

Presentation_ID 52 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv6 Unicast Addresses Structure of an IPv6 Global Unicast Address Subnet ID Used by an organization to identify subnets within its site Interface ID Equivalent to the host portion of an IPv4 address Used because a single host may have multiple interfaces, each having one or more IPv6 addresses

RA message can contain one of the following three options SLAAC Only use the information contained in the RA message SLAAC and DHCPv6 use the information contained in the RA message and get other information from the DHCPv6 server, stateless DHCPv6 (example: DNS) DHCPv6 only device should not use the information in the RA, stateful DHCPv6

IPv6 Unicast Addresses Dynamic Configuration of a Global Unicast Address using DHCPv6 Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Similar to IPv4 Automatically receive addressing information including a global unicast address, prefix length, default gateway address and the addresses of DNS servers using the services of a DHCPv6 server Device may receive all or some of its IPv6 addressing information from a DHCPv6 server depending upon whether option 2 (SLAAC and DHCPv6) or option 3 (DHCPv6 only) is specified in the ICMPv6 RA message Host may choose to ignore whatever is in the routers RA message and obtain its IPv6 address and other information directly from a DHCPv6 server.

IPv6 Unicast Addresses EUI-64 Process or Randomly Generated EUI-64 Process process uses a clients 48-bit Ethernet MAC address, and inserts another 16 bits in the middle of the 46-bit MAC address to create a 64-bit Interface ID advantage is Ethernet MAC address can be used to determine the Interface easily tracked

EUI-64 Interface ID is represented in binary and is made up of three parts: 24-bit OUI from the client MAC address, but the 7th bit (the Universally/Locally bit) is reversed (0 becomes a 1) inserted 16-bit value FFFE 24-bit device identifier from the client MAC address

Automatically created when the global unicast or link-local unicast addresses are assigned Created by combining a special FF02:0:0:0:0:FF00::/104 prefix with the right-most 24 bits of its unicast address. Presentation_ID 74 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IPv6 Multicast Addresses Solicited Node IPv6 Multicast Addresses The solicited node multicast address consists of two parts: FF02:0:0:0:0:FF00::/104 multicast prefix - first 104 bits of the all solicited node multicast address Least significant 24-bits copied from the right-most 24 bits of the global unicast or link-local unicast address of the device Presentation_ID 75 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 8.3 Connectivity Verification Presentation_ID 76 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential ICMP ICMPv4 and ICMPv6 Messages ICMP messages common to both ICMPv4 and ICMPv6 include: Host confirmation Destination or Service Unreachable Time exceeded Route redirection Although IP is not a reliable protocol, the TCP/IP suite does provide for messages to be sent in the event of certain errors, sent using the services of ICMP Presentation_ID 77 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential ICMP ICMPv6 Router Solicitation and Router Advertisement Messages ICMPv6 includes four new protocols as part of the Neighbor Discovery Protocol (ND or NDP): Router Solicitation message Router Advertisement message Neighbor Solicitation message Neighbor Advertisement message Router Solicitation and Router Advertisement Message: Sent between hosts and routers. Router Solicitation (RS) message: RS message is sent as an IPv6 all-routers multicast message Router Advertisement (RA) message: RA messages are sent by routers to provide addressing information Presentation_ID 78 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential ICMP ICMPv6 Router Solicitation and Router Advertisement Messages Presentation_ID 79 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential ICMP ICMPv6 Neighbor Solicitation and Neighbor Advertisement Messages Two additional message types Neighbor Solicitation (NS) Neighbor Advertisement (NA) messages Used for: Address resolution Used when a device on the LAN knows the IPv6 unicast address of a destination but does not know its Ethernet MAC address Duplicate Address Detection (DAD) Performed on the address to ensure that it is unique The device will send a NS message with its own IPv6 address as the targeted IPv6 address Presentation_ID 80 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential ICMP ICMPv6 Neighbor Solicitation and Neighbor Advertisement Messages Presentation_ID 81 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Testing and Verification Ping - Testing the Local Stack Presentation_ID 82 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Testing and Verification Ping Testing Connectivity to the Local LAN Presentation_ID 83 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Testing and Verification Ping Testing Connectivity to Remote Presentation_ID 84 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential Testing and Verification Traceroute Testing the Path Traceroute (tracert) Generates a list of hops that were successfully reached along the path Provides important verification and troubleshooting information If the data reaches the destination, then the trace lists the interface of every router in the path between the hosts If the data fails at some hop along the way, the address of the last router that responded to the trace can provide an indication of where the problem or security restrictions are found Provides round trip time for each hop along the path and indicates if a hop fails to respond Presentation_ID 85 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IP Addressing Summary IP addresses are hierarchical with network, subnetwork, and host portions. An IP address can represent a complete network, a specific host, or the broadcast address of the network. The subnet mask or prefix is used to determine the network portion of an IP address. Once implemented, an IP network needs to be tested to verify its connectivity and operational performance. DHCP enables the automatic assignment of addressing information such as IP address, subnet mask, default gateway, and other configuration information.

Presentation_ID 86 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IP Addressing Summary IPv4 hosts can communicate one of three different ways: unicast, broadcast, and multicast. The private IPv4 address blocks are: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. The depletion of IPv4 address space is the motivating factor for moving to IPv6. Each IPv6 address has 128 bits verses the 32 bits in an IPv4 address. The prefix length is used to indicate the network portion of an IPv6 address using the following format: IPv6 address/prefix length. Presentation_ID 87 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential IP Addressing Summary There are three types of IPv6 addresses: unicast, multicast, and anycast. An IPv6 link-local address enables a device to communicate with other IPv6-enabled devices on the same link and only on that link (subnet). Packets with a source or destination link-local address cannot be routed beyond the link from where the packet originated. IPv6 link-local addresses are in the FE80::/10 range. ICMP is available for both IPv4 and IPv6. Presentation_ID 88 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential